What is the maximum possible acceleration of a car

Question: In the Soapbox Derby, young participants build non-motorized cars with very low-friction wheels. Cars race by rolling down a hill. The track at Akron's Derby Downs, where the national championship is held, begins with a 55ft -long section tilted 13 ? below horizontal. Part A What is the maximum possible acceleration of a car moving down this stretch of track? Express your answer to two significant figures and include the appropriate units.